Process of separating nickel from mattes.



- "UNIT D STATES PATENT OFFICE.

ROBERT H. AIKEN, OF WINTI-IROP HARBOR, ILLINOIS.

PROCESS OF SEPARATING NICKEL FROM MATTES- Specification of Letters Patent.

Patented Sept. 26, 1905.

Application filed March 7, 1903. Serial No. 146,759.

To all whom it may concern:

Beit known that I, ROBERT H. AIKEN, acitizen of the United States, residing at Winthrop Harbor, in the county of Lake and State of Illinois, have invented certain new and useful Improvements in Separation of Nickel from Mattes, of which the following is a specifioathe copper in copper-nickel-sulfid 'matts,

whether or not the latter contain iron. In the process of that application,which includes certain subprocesses, highly -heated nonmolten flux material may be added gradually to molten matte in a converter and the whole subjected to an oxidizing-blast. Where both copper and nickel are present in the matte, 5 the two are not separated from each other'by that process. My present process provides for separating the nickel from the copper, as well as eliminating iron and other metals when they are present. In accordance with this 3 latter process a suitable amount of highlyheated flux material, usually silica or silica plus a small amount of lime, (to lower the fusing-point of the silica-,) is added to molten matte in a converter, the latter preferably 7 being first highly heated and preferably also provided with a thin non-fiuxing lining, the whole beingsubjected to an oxidizing-blast, when the iron in the matte is oxidized and slagged, and before the nickel and copper are 4 materially acted upon this iron slag is removed from the converter by pouringor otherwise. The completion of this stage is indicated by the change in color of the-flame and in the character of the shots thrown from the mouth of the furnace, these indications 5 nickel to oxidize and form a nickel-silicate slag, which is also removed from the converter, leaving the copper sulfid. The completion of g the second stage is known by indications analometals and forming silicates, that action which .2Ou2O plus CuzS equals 60u plus SOz.

gous to those relied upon' at the end of the first stage. Still further blowing gives black copper, as in ordinary processes. These three distinct reactions occur in succession throughselective chemical action depending upon the various heat tonings in oxidizing the different develops the highest temperature effect being the first to occur. For example, with a matte consisting principally of F eS, N iS, and OuzS we have first the formation of FeO, SlOz, and gaseous S02. After the completion of this stage, which gives almost perfect elimination of the iron, there is formation of NiO, SiOz, and S02- After the completion of this second stage and the practically perfect removal of nickel the third and last stage begins, and in this stage thelblowing gives Cu plus S02. It is to be noted that there is a'wide difference or decrease in temperature efiects in the successivestages. Metalliccopperisproduced inthe last stage, because, as is well known, copper under such conditions will not form a silicate to any appreciable extent so long as sulfur is present. The silica, silica and lime, or other flux material is highly heated and usually added progressively during the process of blowing,- but during the first two stages only. The heat produced in blowing the nickel is lower than that produced in blowing on the iron; but the addition of highly-heated flux material not only gives suflicient heat for this stage, but also insures keeping the residue at such a temperature that there is no difliculty in finally finishing the copper.

To determine practically the points at which the iron and the nickel are to be poured off, 9 the operator should be familiar with the different products with which he deals, the color of the flames at the mouth of the converter, and the varying temperature of the bath. The dividing-line between the steps need not be determined with great accuracy, however, for no serious harm results in case either pointbe passed. In other words, if the iron be not poured off as soon as it is all slagged the nickel that then passes into the slag is recovered in resmelting, and similarly when the nickel is all slagged to a silicate no copper silicate will be formed until the copper is blown to a' metal, in accordance with the well-known reaction, To determine the points in question near enough for practical purposes, the operator judges by the shots from the mouth of the converter,

always indicative of character, by the drop in volume and temperature of the flame, and by changes in the color of the flame. A clearing up of the flame and a clear blue flame, for example, indicate the absence of iron, and a marked drop in the volume of the flame, with a tinge of red, indicate that the nickel is completely slagged. Workmen familiar with the copper-converter processes as carried on in the present state of the art readily understand such indications and find no material difficulty in pouring off at proper times.

The nickel silicate or slag produced is comparatively free from other metals owing to the fact that the more freely oxidizable and volatile metals are eliminated during the first stage, while those of greater stability remain with the copper.

The nickel silicate obtained as above set forth is reduced in a suitable furnace by the substitution at high temperature of strong bases, such as OaO and MgO and the reduction of nickel oxid to crude nickel, in this case practically free from metals which would not be readily eliminated by electrolysis.

In the above description the matte has been supposed to contain iron, which was first eliminated. Obviously my invention also includes the separation of nickel from coppernickel-sulfid mattes originally free from iron or from which the iron may have been removed.

The flux used contains not less than seventy per cent. of silica, and hence is hardly fusible at ordinary furnace temperature; but it does not matter whether it fuses or not. The temperature of the added flux need never be above 1,700 centigrade, and it may be far below and even as low as 800 centigrade when the converter and its contents are at a high temperature.

What I claim is-- 1. The method of separating nickel from copper-nickel-sulfid mattes which consists in adding to molten matte in a converter suitable highly-heated flux material, principally silica, subjecting the whole to an air-blast to oxidize the nickel and removing the nickel-silicate slag thus formed before the blast has materially acted upon the copper.

cipally silica, subjecting the whole to an airblast to oxidize the nickel and removing the nickel-silicate slag thus formed before the blast has materially acted upon the copper.

4:. The process of separating nickel l'rom copper-nickel-sullid mattes which consists in adding highly-heated flux material principally silica to molten matte in a converter, subjecting the whole to an oxidizing-blast, removing the iron slag thus formed after approximately all the iron is blown to a silicate,

again adding such highly-heated liux material, slagging the nickel, and pouring oil' the nickel-silicate slag thus formed before the blast has materially acted upon the copper.

5. The process of separating nickel from copper-nickel-suliid mattes which consists in adding highly-heated non-molten flux material principally silica to molten matte in a converter, subjecting the whole to an oxidizingblast, removing the iron slag thus formed after approximately all the iron is blown to a silicate, again addingsuch highly-heated nonmolten fiux material, slagging the nickel, and removing from the converter the nickel-silicate slag thus formed before the blast has materially acted upon the copper.

6. The process of separating nickel from copper-nickel-sulfid mattes which consists in progressively adding highly-heated flux material principally silica to molten matte in a converter, subjecting the whole to an oxidizing-blast, removing from the converter the iron slag thus formed after approximately all the iron is blown to a silicate, again adding progressively such highly-heated iiux material, slagging the nickel, and removing from the converter the nickel-silicate slag thus formed before the blast has materially acted upon the copper.

7. The method of separating nickel from copper-nickel-sulfid mattes which consists in adding to molten matte in a converter highlyheated flux material containing not less than seventy percent. of silica, subjecting the whole to an air-blast to oxidize the nickel, and removing the nickel-silicate slag thus formed before the blast has materially acted upon the copper.

8. The process of separating nickel from copper-nickel-sulfid mattes which consists in adding highly-heated iiux material containing not less than seventy per cent. of silica to molten matte in a converter, subjecting the Whole to an oxidizing-blast, removing the iron slag thus formed after approximately all the iron is blown to a silicate, again adding such flux material, slagging the nickel, and pouring otf the nickel silicate slag thus formed before the blast has materially acted upon the copper.

9. The method of separating nickel from copper-nickel-sulfid mattes which consists in adding to molten matte in a converter flux material, containing not less than seventy per In testimony whereofIhave signed iny name cent. of silica, at a temperature between 800 to this specification in presence of two Witand 1,700 centigrade subjecting the whole to nesses.

an air-blast to oxidize the nickel and remov- ROBERT H. AIKEN. ing from the converter the nickel-silicate slag Witnesses: thus formed before the blast has materially WALLACE GREENE,

acted upon the copper. l EDWIN S. OLARKsoN. 

